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, Volume 15 Issue 2 Previous Issue    Next Issue
Articles
Analysis of endophytic fungi in roots of Santalum album Linn. and its host plant Kuhnia rosmarinifolia Vent.
Si-sheng Sun, Xiao-mei Chen, Shun-xing Guo
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2014, 15(2): 109-115.   https://doi.org/10.1631/jzus.B1300011
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Santalum album Linn. is an evergreen and hemi-parasitic tree, the heartwood-sandalwood of which was used during a long history in traditional Chinese medicine. Kuhnia rosmarinifolia Vent. is a good host for 1- or 2-year-old growing S. album. The interaction between S. album and K. rosmarinifolia is still little known. Many studies have been carried out on a number of plants for identification and diversity of endophytes. In this study, in total 25 taxa of endophytic fungi were isolated from the roots of S. album and the roots of K. rosmarinifolia. The most frequently isolated genera were Penicillium sp. 1 and Fusarium sp. 1 in the roots of S. album and K. rosmarinifolia, respectively. S. album is a root parasite of K. rosmarinifolia. The interesting result is that they apparently do not share the same endophytic fungi isolates. This study for the first time explored the content of endophytic fungi from S. album and K. rosmarinifolia, which provides important information for further studies.
Improvement of a gene targeting system for genetic manipulation in Penicillium digitatum
Qian Xu, Cong-yi Zhu, Ming-shang Wang, Xue-peng Sun, Hong-ye Li
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2014, 15(2): 116-124.   https://doi.org/10.1631/jzus.B1300213
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Penicillium digitatum is the most important pathogen of postharvest citrus. Gene targeting can be done in P. digitatum using homologous recombination via Agrobacterium tumefaciens mediated transformation (ATMT), but the frequencies are often very low. In the present study, we replaced the Ku80 homolog (a gene of the non-homologous end-joining (NHEJ) pathway) with the hygromycin resistance cassette (hph) by ATMT. No significant change in vegetative growth, conidiation, or pathogenicity was observed in Ku80-deficient strain (螖PdKu80) of P. digitatum. However, using 螖PdKu80 as a targeting strain, the gene-targeting frequencies for both genes PdbrlA and PdmpkA were significantly increased. These results suggest that Ku80 plays an important role in homologous integration and the created 螖PdKu80 strain would be a good candidate for rapid gene function analysis in P. digitatum.
Analysis of promoters of microRNAs from a Glycine max degradome library
Yi-qiang Han, Zheng Hu, Dian-feng Zheng, Ya-mei Gao
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2014, 15(2): 125-132.   https://doi.org/10.1631/jzus.B1300179
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Objective: MicroRNAs (miRNAs) are genome-encoded, small non-coding RNAs that play important functions in development, biotic and abiotic stress responses, and other processes. Our aim was to explore the regulation of miRNA expression. Methods: We used bioinformatics methods to predict the core promoters of 440 miRNAs identified from a soybean (Glycine max) degradome library and to analyze cis-acting elements for 369 miRNAs. Results: The prediction results showed that 83.86% of the 440 miRNAs contained promoters in their upstream sequences, and 8.64% (38 loci) in their downstream sequences. The distributions of two core promoter elements, TATA-boxes and transcription start sites (TSSs), were similar. The cis-acting elements were examined to provide clues to the function and regulation of spatiotemporal expression of the miRNAs. Analyses of miRNA cis-elements and targets indicated a potential auxin response factor (ARF)- and gibberellin response factor (GARF)-mediated negative feedback loop for miRNA expression. Conclusions: The features of miRNAs from a Glycine max degradome library obtained here provide insights into the transcription regulation and functions of miRNAs in soybean.
Molecular variability and evolution of a natural population of tomato yellow leaf curl virus in Shanghai, China
Xiu-ling Yang, Meng-ning Zhou, Ya-juan Qian, Yan Xie, Xue-ping Zhou
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2014, 15(2): 133-142.   https://doi.org/10.1631/jzus.B1300110
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Tomato yellow leaf curl virus (TYLCV), belonging to the genus Begomovirus of the family Geminiviridae, is emerging as the most destructive pathogen of tomato plants. Since the first report of TYLCV in Shanghai, China in 2006, TYLCV has spread rapidly to 13 provinces or autonomous regions of China. In this study, the molecular variability and evolution of TYLCV were monitored in Shanghai from its first upsurge in 2006 until 2010. Full-length genomic sequences of 26 isolates were obtained by rolling circle amplification. Sequence analysis showed that the intergenic region was the most variable, with a mean mutation rate of 4.81×10−3 nucleotide substitutions per site per year. Genetic differentiation was found within isolates obtained from 2006, 2009, and 2010, though a linear increase in genetic diversity over time was not evident. Whilst significant parts of TYLCV genes were under negative selection, the C4 gene embedded entirely within the C1 gene had a tendency to undergo positive selection. Our results indicate that a mechanism of independent evolution of overlapping regions could apply to the natural population of TYLCV in Shanghai, China.
Stability and cytotoxicity of angiotensin-I-converting enzyme inhibitory peptides derived from bovine casein
Wei Wu, Pan-pan Yu, Feng-yang Zhang, Hong-xia Che, Zhan-mei Jiang
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2014, 15(2): 143-152.   https://doi.org/10.1631/jzus.B1300239
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This study investigated the effect of heat treatment combined with acid and alkali on the angiotensin-I-converting enzyme (ACE) inhibitory activity of peptides derived from bovine casein. The free amino group content, color, and cytotoxicity of the peptides were measured under different conditions. When heated at 100 °C in the pH range from 9.0 to 12.0, ACE inhibitory activity was reduced and the appearance of the peptides was significantly darkened. After thermal treatment in the presence of acid and alkali, the free amino group content of ACE inhibitory peptides decreased markedly. High temperature and prolonged heating also resulted in the loss of ACE inhibitory activity, the loss of free amino groups, and the darker coloration of bovine casein-derived peptides. However, ACE inhibitory peptides, within a concentration range of from 0.01 to 0.2 mg/ml, showed no cytotoxicity to Caco-2 and ECV-304 cell lines after heat treatment. This indicated that high temperature and alkaline heat treatment impaired the stability of bovine casein-derived ACE inhibitory peptides.
Cytotoxicity and enhancement activity of essential oil from Zanthoxylum bungeanum Maxim. as a natural transdermal penetration enhancer
Yi Lan, Qing Wu, Ying-qiu Mao, Qiong Wang, Jing An, Yan-yan Chen, Wen-ping Wang, Bo-chen Zhao, Na Liu, Ye-wen Zhang
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2014, 15(2): 153-164.   https://doi.org/10.1631/jzus.B1300230
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The aim of this present study is to investigate the effect of Zanthoxylum bungeanum oil (essential oil from Z. bungeanum Maxim.) on cytotoxicity and the transdermal permeation of 5-fluorouracil and indomethacin. The cytotoxicity of Z. bungeanum oil on dermal fibroblasts and epidermal keratinocytes was studied using an MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The rat skin was employed to determine the percutaneous penetration enhancement effect of Z. bungeanum oil on hydrophilic and lipophilic model drugs, i.e., 5-fluorouracil and indomethacin. The secondary structure changes of the rat stratum corneum (SC) were determined using attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and saturated solubilities and SC/vehicle partition coefficients of two model drugs with and without Z. bungeanum oil were also measured to understand its related mechanisms of action. It was found that the half maximal inhibitory concentration (IC50) values of Z. bungeanum oil were significantly lower in HaCaT and CCC-ESF-1 cell lines compared to the well-established and standard penetration enhancer Azone. The Z. bungeanum oil at various concentrations effectively facilitated the percutaneous penetration of two model drugs across the rat skin. In addition, the mechanisms of permeation enhancement by Z. bungeanum oil could be explained with saturated solubility, SC/vehicle partition coefficient, and secondary structure changes of SC.
Production of a monoclonal antibody against oxytetracycline and its application for oxytetracycline residue detection in shrimp
Tossapon Wongtangprasert, Wirongrong Natakuathung, Umaporn Pimpitak, Anumart Buakeaw, Tanapat Palaga, Kittinan Komolpis, Nanthika Khongchareonporn
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2014, 15(2): 165-172.   https://doi.org/10.1631/jzus.B1300181
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A novel monoclonal antibody (MAb) against oxytetracycline (OTC) was generated and characterized. The MAb was used in the development of an enzyme-linked immunosorbant assay (ELISA)-based detection system. An OTC-bovine serum albumin (BSA) conjugate was prepared and used in the immunization of mice. A conventional somatic cell fusion technique was used to generate MAb-secreting hybridomas denoted 2-4F, 7-3G, and 11-11A. An indirect competitive ELISA (icELISA) was applied to measure the sensitivity and specificity of each MAb in terms of its 50% inhibitory concentration (IC50) and percentage of cross-reactivity, respectively. MAb 2-4F exhibited the highest sensitivity, with an IC50 of 7.01 ng/ml. This MAb showed strong cross-reactivity to rolitetracycline, but no cross-reactivity to other unrelated antibiotics. When MAb 2-4F was used to detect OTC from shrimp samples, the recoveries were in the range of 82%–118% for an intra-assay and 96%–113% for an inter-assay. The coefficients of variation of the assays were 3.9%–13.9% and 5.5%–14.9%, respectively.
In vitro antioxidant activity and potential inhibitory action against α-glucosidase of polysaccharides from fruit peel of tea (Camellia sinensis L.)
Yue-fei Wang, Jie Wang, Jing Wu, Ping Xu, Yi-qi Wang, Jun-jie Gao, Danielle Hochstetter
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2014, 15(2): 173-180.   https://doi.org/10.1631/jzus.B1300186
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The conditions for extracting polysaccharides from tea (Camellia sinensis L.) fruit peel (TFPPs) were studied. Three parameters (temperature, time, and liquid/solid ratio) affecting the extraction of TFPP were optimized using response surface methodology (RSM). Under the optimized conditions, the yield of TFPP was predicted to be 4.98%. The physicochemical properties, in vitro antioxidant activities, and inhibitory effects on α-glucosidase of fractionated TFPPs (TFPP-0, TFPP-20, TFPP-40, and TFPP-60) were investigated. We found that the TFPPs were all acid protein-bound heteropolysaccharides, although with different chemical compositions. They had not only remarkable scavenging activity on 2,2\'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) and reducing activity, but also excellent inhibitory potential against α-glucosidase in vitro. Our results suggest that tea fruit peel could be treated as a potential bioresource for the development of polysaccharide antioxidants.
Response of seed tocopherols in oilseed rape to nitrogen fertilizer sources and application rates
Nazim Hussain, Hui Li, Yu-xiao Jiang, Zahra Jabeen, Imran Haider Shamsi, Essa Ali, Li-xi Jiang
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2014, 15(2): 181-193.   https://doi.org/10.1631/jzus.B1300036
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Tocopherols (Tocs) are vital scavengers of reactive oxygen species (ROS) and important seed oil quality indicators. Nitrogen (N) is one of the most important fertilizers in promoting biomass and grain yield in crop production. However, the effect of different sources and application rates of N on seed Toc contents in oilseed rape is poorly understood. In this study, pot trials were conducted to evaluate the effect of two sources of N fertilizer (urea and ammonium nitrate). Each source was applied to five oilseed rape genotypes (Zheshuang 72, Jiu-Er-1358, Zheshuang 758, Shiralee, and Pakola) at three different application rates (0.41 g/pot (N1), 0.81 g/pot (N2), and 1.20 g/pot (N3)). Results indicated that urea increased 伪-, 纬-, and total Toc (T-Toc) more than did ammonium nitrate. N3 was proven as the most efficient application rate, which yielded high contents of 纬-Toc and T-Toc. Highly significant correlations were observed between Toc isomers, T-Toc, and 伪-/纬-Toc ratio. These results clearly demonstrate that N sources and application rates significantly affect seed Toc contents in oilseed rape.
Immunocytochemical localization of carbonic anhydrase in the pseudobranch tissue of the rainbow trout Oncorhynchus mykiss
S. M. Rahim, A. G. Mazlan, K. D. Simon, J. P. Delaunoy, P. Laurent
Journal of Zhejiang University-SCIENCE B (Biomedicine & Biotechnology), 2014, 15(2): 194-200.   https://doi.org/10.1631/jzus.B1200297
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Pseudobranch function has long interested scientists, but its role has yet to be elucidated. Several studies have suggested that pseudobranchs serve respiratory, osmoregulatory, and sensory functions. This work investigated the immunolocalization of pseudobranch carbonic anhydrase (CA) in the teleost fish species rainbow trout (Oncorhynchus mykiss) to clarify its physiological function. CA was purified from rainbow trout gills O. mykiss and specific antibodies were raised. Immunoblotting between tissue homogenates of pseudobranch and gill CA antibodies showed specific immunostaining with only one band corresponding to CA in the pseudobranch homogenate. Results of immunohistochemical technique revealed that CA was distributed within pseudobranch cells and more precisely in the apical parts (anti-vascular) of cells. The basal (vascular) parts of cells, tubular system, blood capillaries, and pillar cells were not immunostained. Immunocytochemistry confirmed these results and showed that some CA enzyme was cytoplasmic and the remainder was linked to membranous structures. The results also showed that the lacunar tissue layers did not display immunoperoxidase activity. Our results indicated that pseudobranch CA may have a function related to the extracellular medium wherein CA intervenes with the mechanism of stimulation of afferent nerve fibers.
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